1. Technical Field
The present invention relates to an optical reception and transmission module.
2. Related Art
In IC technology and LSI technology, it has been noticed that in order to improve operating speed and integration level, optical wiring is mounted between devices, between boards in devices, and between chips in devices instead of mounting high-density electric wiring. In some cases, an optical reception and transmission module with an optical waveguide film is used to realize this optical wiring.
In such an optical reception and transmission module, as a connection method between a surface light emitting element or a surface light receiving element and an optical waveguide, there are proposed (1) a method in which a surface element is stood at 90° and is connected to an optical waveguide, (2) a method in which a 90-degree turning back mirror is used between a surface element and a waveguide and connects them, (3) a method in which a 90-degree turning back mirror is formed in a waveguide and the waveguide connects to a surface element, (4) a method in which a waveguide is stood vertically and connects to a surface element, and the like.
However, in the method of (1), there is a problem with electrode wiring of the surface element, that is, in that the electrode wiring by wire bonding may not be mounted. In the method of (2), there is a problem in that a lens is required besides the external mirror, resulting in an increase in cost, and a difficulty in downsizing. In the method of (3), although the mounting is easy, there have remained a problem with limited performance of the 90-degree turning back mirror, and a problem with cost as a mobile application, such as exchange of an optical waveguide film, compatibility between solder heat resistance and bending performance. In the method of (4), there are problems with mountability of the waveguide and bending a waveguide, and thus, there are many problems with mounting size and the like in the mobile application so that the method is impractical.
As a representative example of the method of (3), there has been known a technique in which a 45-degree mirror is manufactured by a dicer to be utilized for converting an optical path. In this constitution, however, it is difficult to satisfy both of bending performance required especially when it is used in the mobile application or the like, and heat resistance for withstanding heat applied during sealing of wire bonding in mounting, or the like.